Users of the iPhone 4S download almost three times more data than iPhone 3GS owners, a study from network firm Arieso shows, placing the blame on Siri, the voice-enabled assistant exclusive to Apple’s latest smartphone. Even compared to iPhone 4 owners, iPhone 4S users are the hungriest, using twice as much data -- but is Siri really to blame?

The Arieso study compares data consumption of users of the newest smartphones against the iPhone 3G and finds that Android phones are at the top of the table for uplink data volumes, with HTC Desire S users uploading on average 3.23 times as much data as iPhone 3G users. The iPhone 4S users logged just under, at 3.20 times more data.

Siri requires an active Internet connection in order to function. Arieso’s Chief Technology Officer Michael Flanagan says that this constant connection to Apple’s servers, including processing Siri requests and keeping iCloud services in sync, is to blame for the increase in data usage, noting that a minority of users account for half of downloaded data.

The findings from Arieso contrast with tests performed by ArsTechnica on data usage generated by Siri. In those tests, 11 search queries performed every single day for 30 days over 3G led to an increase of 20MB in data usage. Similarly, those who used Siri less frequently -- around four to six times per day -- used around 11MB extra in a month, so even if you are on the lowest data plan, using Siri shouldn’t make a significant dent in data usage.

Alternatively, my personal data allowance records on the iPhone 4S show that while using Siri at least three or four times daily (mainly over 3G, in the car), I received just 645MB of data and sent 221MB since October 15, 2011, which is consistent with average data usage during ownership of an iPhone 3GS.

Of course, your mileage may vary, depending on whether you connect to Wi-Fi at home and work, but it’s hard to see Siri gobbling large amounts of data. Perhaps using automatic iCloud sync over 3G for iTunes purchases could bump up your data usage, but even then, files over 20MB can be downloaded only over Wi-Fi. If ever in doubt about your 3G data consumption, check usage on your iPhone via Settings/Usage/Cellular Usage.